Freezing PS3

Hi all, can anybody help?

I've bought a psp with a broken blu ray drive. It has the shell of the old drive with the logic board on it. The problem is it works fine through the menus but when I try and play a downloaded demo, the screen goes black and everthing becomes unresponsive. I've tried various demos just incase one was corrupt. Also if I go to playstation home, it freezes too.

Is this because of the faulty blu ray or is there a more serious issue? I have tried all the maintenance techniques such as restore file system, rebuild database and restore ps3 system. I've also done a full format of the hard drive. All of which failed to work.

If I get a replacement Blu ray drive will it fix this problem?

Sorry for all the questions but there is no repair shops around my location and I just don't want to shell out more money if it's a waste of time.